Photoshop CS6: Genius i608x sometime gets pressure problems

I have a Genius i608x drawing tablet and a Photoshop CS6 program. I usually use Paint Tool SAI, but recently I moved to Photoshop. I can draw anything I like without any pressure problem on some programs like SAI, CLIP Studio Paint, etc., except Photoshop. I've tried on any Photoshops that I have, like Photoshop CS6, CS5, and CS3 (portable), but I sometime get pressure problems. When I drew something, the pressure worked fine. But SOMETIMES in the middle when I drew something, suddenly I got pressure problem and when I continue to draw, the pressure problems suddenly disappear. And if I keep continuing my drawing, the pressure problems sometime appears, too.
I've updated my driver for the newest version and still not working.
I've been searching on any kind of websites to fix this problem, but I got nothing.

Almost always, the problem is in the tablet driver software. Sometimes it is due to a setting in the OS that alters the behavior of the tablet (like double click distance options, or Windows ink options).